Removes FieldStats API (#25628)

* Removes FieldStats API

* iter

* iter

Author: colings86

core/src/main/java/org/elasticsearch/action/ActionModule.java

@@ -156,8 +156,6 @@
 import org.elasticsearch.action.fieldcaps.FieldCapabilitiesAction;
 import org.elasticsearch.action.fieldcaps.TransportFieldCapabilitiesAction;
 import org.elasticsearch.action.fieldcaps.TransportFieldCapabilitiesIndexAction;
-import org.elasticsearch.action.fieldstats.FieldStatsAction;
-import org.elasticsearch.action.fieldstats.TransportFieldStatsAction;
 import org.elasticsearch.action.get.GetAction;
 import org.elasticsearch.action.get.MultiGetAction;
 import org.elasticsearch.action.get.TransportGetAction;
@@ -213,7 +211,6 @@
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestHandler;
 import org.elasticsearch.rest.action.RestFieldCapabilitiesAction;
-import org.elasticsearch.rest.action.RestFieldStatsAction;
 import org.elasticsearch.rest.action.RestMainAction;
 import org.elasticsearch.rest.action.admin.cluster.RestCancelTasksAction;
 import org.elasticsearch.rest.action.admin.cluster.RestClusterAllocationExplainAction;
@@ -493,7 +490,6 @@ public <Request extends ActionRequest, Response extends ActionResponse> void reg
         actions.register(GetStoredScriptAction.INSTANCE, TransportGetStoredScriptAction.class);
         actions.register(DeleteStoredScriptAction.INSTANCE, TransportDeleteStoredScriptAction.class);
 
-        actions.register(FieldStatsAction.INSTANCE, TransportFieldStatsAction.class);
         actions.register(FieldCapabilitiesAction.INSTANCE, TransportFieldCapabilitiesAction.class,
             TransportFieldCapabilitiesIndexAction.class);
 
@@ -607,7 +603,6 @@ public void initRestHandlers(Supplier<DiscoveryNodes> nodesInCluster) {
         registerHandler.accept(new RestPutStoredScriptAction(settings, restController));
         registerHandler.accept(new RestDeleteStoredScriptAction(settings, restController));
 
-        registerHandler.accept(new RestFieldStatsAction(settings, restController));
         registerHandler.accept(new RestFieldCapabilitiesAction(settings, restController));
 
         // Tasks API